The present invention is related to an oil-immersed and high-pressure tripping switch structure, comprising an operational apparatus, an arc-extinguishing cylinder, and an oil-shortage automatic tripping safety device wherein a sensory device detecting a fault current will trip open to displace a spring rebound pivoting-point, permitting a main spring to simultaneously actuate the release of contact points and the rotation of an operational handle therewith so that the operational handle is rotated to recover its primary angle so as to indicate the tripped/off status of the switch, facilitating the judgment and operation of workers. In addition, via a buoyant tube combined with an oil-retaining tank, the buoyant tube in case of oil-shortage can generate sufficient downward-pressure to activate the release of a tripping device so as to ensure the safety of the present invention in operation. Furthermore, a complex arc-quenching mechanism is applied so that the arc-extinguishing cylinder can efficiently break higher fault current thereby.
Please refer to FIGS. 1-A, 1-B, 1-C, and 1-D. For decades, oil-immersed and high-pressure tripping switches have been applied to transformers to prevent the over-current condition thereof. A conventional oil-immersed and high-pressure tripping switch usually found on the market utilizes a fixed spring rebound pivoting-point R1, and a tripping mechanism having a ring-shaped trip spring R5 applied thereto. To set the switch in operation, an actuating linkage rod R4 of a tripper R3 is first connected to a contact point crank R5 and a main spring rotating crank R6. Meanwhile, the ring-shaped trip spring R2 is built up in strength as shown in FIG. 1-A. An operational handle R7 is rotated to activate the stretching movement of a main spring R8. When the main spring R8 is rotated to exceed the rebound pivoting-point R1, the main spring R8 will contract in opposite directions as shown in FIG. 1-B, speedily actuating the movement of the main spring rotating crank R6 and the contact point crank R5 therewith so as to allow a movable contact point R9 of the switch thereof to close onto a fixed contact point RIO as shown in FIG. 1-C. And a switch current sensory device R11 detecting a fault current will activate the tripper R3 and the actuating linkage rod R4 therewith, releasing the contact point crank R5 to detach from the main spring rotating crank R6. Meanwhile, the ring-shaped trip spring R2 will undergo an expansion movement to actuate the contact point crank R5 rotating downwards and making the movable contact point R9 to detach from the fixed contact point R10 thereof. Due to the main spring R8 still remained in the first adjusted status, the operational handle R7 will stay in the former switched-on position as shown in FIG. 1-D. Therefore, a worker can't judge from the external look of the switch if it has been shutdown in a tripped status, which can not only increase the chance of accident, but may easily cause mistakes in operation thereof.
In case of a leakage of the insulating oil due to the corrosion or breaking of the case of the transformer, the continuity in the supply of electricity will result in the insufficient insulation distance and cause the accident of electrical-arc blast. At present, the high-pressure tripping switch on the market cannot detect the shortage of oil and automatically trip off in case of the oil-shortage. Thus, in addition to the failure to insulate the transformer in advance before it works under the condition of insufficient oil, the conventional high-pressure tripping switch under the shortage of insulating oil may fail to successfully cut off the supply of electricity and break the circuit thereof, which can lead to the disaster of electrical-arc blast and endanger the lives of workers.
Moreover, the arc-extinguishing cylinder of the conventional high-pressure tripping switch is designed in a half-enclosed form so as to reduce the pressure of the vaporized oil generated in the process of arc-interruption, which makes it to trip at rather small fault current. As a result, series of low-current and backup fuses must be strung to match with the conventional high-pressure tripping switch. Thus, the conventional high-pressure stripping switch is uneconomically limited in the range of protection thereof.